Membership Ring of the Electronic Illuminati

When the cabal of electronic design gurus that pull the invisible strings of the hardware world get together, we imagine they have to show this ring to prove their identity. This is the work of [Zach Fredin], and you’re going to be shocked by the construction and execution of what he calls Cyborg Ring.

The most obvious feature of the Cyborg Ring is the collection of addressable LEDs that occupy the area where gems would be found on a ring. What might not be so obvious is that this is constructed completely of electronic components, and doesn’t use any traditional mechanical parts like standoffs. Quite literally, the surface mount devices are structural in this ring.

They are also electrical. Here you can see a detail of how [Zach] pulled this off. We are looking at the underside of the ring, the part that goes below your knuckle. One of the two PCBs that are sized to fit your finger has been placed in a Stick Vise while the QFN processor is soldered on end, and the pairs of SMD resistors are put in place.

The precise measurements of each part make it possible to choose components that will perfectly span the gap between the two boards. In the background of the image you can see SMD resistors on their long ends — a technique he used to allow the LEDs themselves to span between one resistor on each of the two PDBs to complete the circuit. Incredible, right?

But it gets better. [Zach] ended up with a working prototype, but has continued to forge ahead with new design iterations. These updates are a delight to read! Make sure you follow his project and check in regularly; if you’ve already looked at this now’s the time to go back and see the new work. The gold pads for the minuscule coin cells which power the ring are being reselected as the batteries didn’t fit well on the original. Some layout problems are being tweaked. And the new spin of boards should be back from fab in a week or so.

Don’t miss the demo video found below. We really like seeing projects that build within the wearble ring form factor. It’s an impressive constraint which [Zach] seems to have mastered. Another favorite of ours is [Kevin’s] Arduboy ring.

I think it would be possible; the batteries need around 6mm of clearance, so it would make the ring taller. Tradeoffs, tradeoffs.. the batteries are definitely the fussy part to fit in on this project.

I like the rechargable battery idea for practical (i.e. waterproofing) reasons, but the energy density is quite a bit worse. The Zn cells are only 1.4v, but they have 100mAh capacity — 100x the Seiko rechargable.

True. You need to get a proper Li-ion cell to get good capacity, but the smallest I’ve seen those is 20mm OD. On the other hand, is 1mah enough to last 8-12 hours? If it is, just take the ring off and recharge it overnight. Also, the exposed gold charging and programming contacts should survive liquid immersion as long as they’re all at the same voltage.

Just make the PCB act as an antenna, then make a wrist band with bigger LiPo cells and a wireless energy transmitter. (probably a bit hard to cover that distance without loosing to much energy)
Or use some kind of energy harvesting circuit that can collect trace amounts of energy (maybe RF, or some photodiodes acting as solar cells?), load up a little ultracap with that, and release the electrons out into the LEDs as soon as it has collected enough energy. Something like the CPC1822 (obsolete i think) or BPW34 could work as a tiny solar cell that you could harvest ;)

Right now the constraint is durability; hopefully the next rev solves some of those issues. Zn-air cells are only good for 4-6 weeks after popping off the tabs, and it should be easy enough to get the average current draw low enough that battery capacity isn’t the limiting factor. Mostly depends how often the LEDs are on.

I think they should just make the LEDs light randomly and say it is some sort of “Jupiter’s 3rd Moon Binary Clock”. That is what I call my projects that blink and have no function haha.
Neat design though. For the battery problems mentioned above, how about some sort of engagement ring battery that snuggles up to it.

Nice work! Turns out I am working on a very similar project. I am in the moulding / casting stage at the moment, and have the pcb designed, though not manufactured due to Chinese New Year. I will be posting my ring design, as soon as the PCB is checked. It is fascinating and challenging form factor. Your design is a piece of art I must say!